Re: troubleshooting tesla coil, continued (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Thu, 13 Sep 2007 21:20:03 -0500
From: Bert Hickman <bert.hickman@xxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: troubleshooting tesla coil, continued (fwd)

Tesla list wrote:
> ---------- Forwarded message ----------
> Date: Thu, 13 Sep 2007 19:19:45 -0400
> From: Marko Ruban <Marko@xxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: troubleshooting tesla coil, continued
> 
> Hello guys, I'm back from a long summer vacation.  As per previous 
> suggestions I have acquired an old NST transformer (12kV, 60Hz, 60mA 
> output).  And the spark gap does run now with capacitor/primary in 
> circuit.  However, there's no visible effect on the topload, still.  
> Could it be that badly un-tuned?
> 
> Please see the photo of my simple setup and make any suggestions...
> http://marko.dppl.com/TC_setup.jpg
> 
> The flat rectangular thing in front, is the capacitor, which should be 
> about 7pF.  Can't make a more specific measurement since my new 
> multimeter is still in the mail.  Spark gap is on top of the NST, and 
> consists of two screws facing each other (about 0.2" adjustable 
> spacing).  Wire running in the back to the right is the ground.
> 
> Also, here's a dump of JavaTC for my coil...
> http://marko.dppl.com/coil.txt
> 
> Thanks in advance for any assistance.
> 

Hi Marko,

The main problem is that your tank cap is about 1000X too small. JavaTC 
indicates you need 0.007 uF, or 7,000 pF. Once you get the right size 
cap, you'll begin to get results. The spark gap should also have 
multiple segments (copper pipe is excellent) and be cooled with a small 
fan. This will likely require you to make a larger topload to prevent 
discharges from breaking out from the top of your secondary winding.

Good luck and play safely!

Bert
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